Candidate: Sylvia Becker, MD, MPH is an NRSA-Primary Care Research Fellow in the Department of Family Medicine at the University of North Carolina at Chapel Hill (UNC). Career Development Plan: the candidate Will conduct mentored research and strengthen vital knowledge in global health research. The candidate will be positioned to become leader in vaccine effectiveness in the developing world. Immediate Objective: to acquire expertise in infectious disease epidemiology and vaccine effectiveness; to assess the effectiveness ofthe rotavirus vaccine in a developing world setting. Long-term Objective: to provide evidence on vaccine effectiveness for developing world decision makers. Specific Aims: 1) Determine the effectiveness ofthe rotavirus vaccine in the primary care setting. 2) Characterize the circulating genotypes of the virus following UIRI implementation. 3) Determine the effect of UIRI on the childhood diarrhea incidence rate in a community. Research Methods: In Aim 1, we will a case control design to determine the vaccine's effectiveness in reducing primary care visits among children for rotavirus diarrhea at eight primary care centers in Leon, Nicaragua. In Aim 2, we will characterize the genotypes among all rotavirus-positive stool samples collected in Aim 1 and explore whether type replacement may be occurring. In Aim 3, we will measure the diarrhea incidence rate among children in the community using a population-based sample provided by an existing Surveillance System based at University of Nicaragua, Leon (UNAN) and compare to the incidence prior to universal rotavirus immunization. Environment: we will work with eight primary care centers in Leon that have a long history of collaboration with members of the research team. Laboratory studies for Aim 1 will be carried out in a laboratory at UNAN while those for Aim 2 will be carried out at the CDC. Aim 3 will make use of an existing Surveillance System that has an international reputation for the quality of its research. Database management is within this Surveillance System. Mentorship: primary mentorship at the UNC will be provided by epidemiologist and infectious disease specialist, David J. Weber, MD, MPH. Primary mentorship at UNAN will be provided by Felix Espinoza, MD, PhD (Aims 1 and 2) and Rodolfo Peria, MD, PhD (Aim 3). Additional mentorship is provided by leaders in rotavirus epidemiology and vaccine effectiveness, Drs. Umesh Parashar and Manish Patel, by medical geographer, Micheal Emch, PhD, by biostatistician, Michael Hudgens, PhD, by vaccine epidemiologist Jennifer Smith, PhD, MPH, and by gastroenterologist, Douglas Morgan, MD, MPH, who has led the UNC-UNAN research collaboration. PUBLIC HEALTH RELEVANCE: We have the unique opportunity in Leon, Nicaragua to determine the effect of UIRI on the primary care and community levels. At the end of the proposed study, we would provide needed information to others in the developing world who are currently considering adding rotavirus vaccines to their vaccine armamentarium.